It has long been desirable to have a removable auxiliary lens assembly attached to eyeglasses. Often, these auxiliary lens assemblies are hinged to rotate between raised and lowered positions. Professional baseball players have used these “flip-up” auxiliary lenses for more than four decades to protect their eyes from the sun, but to allow them unrestricted vision in the event the ball was hit in their vicinity without the necessity of removing the auxiliary lens assembly from the primary assembly altogether. These “flip-up” lenses are attached by a hinged mechanism to the primary lens assembly so that they can be raised and lowered or moved between an “up” position, away from the primary lenses, and a “down” position, where the auxiliary lenses cover or overlap the primary lenses.
Various means have been provided for attaching a flip-up or hinged auxiliary lens assembly to a primary lens assembly. Typically, the means of attachment between the primary and auxiliary lens assembly is either complex and difficult and expensive to manufacture, or flimsy (and easily manufactured). One problem is that the attachment point must be carefully selected at the design stage so that the auxiliary lenses can “flip-up”: the auxiliary lens assembly must be able to clear the primary lens assembly when it its rotated between the up and down or raised and lowered positions. This need is not addressed by the prior art.
A need exists, therefore, for improved means for attachment of hinged auxiliary lens assemblies to primary lens assemblies that is both robust in its attachment, yet easily manufactured and permits breadth in design characteristics.